aboard

on or onto a ship, plane, bus or trainsynonymon boardWe went aboard.He was already aboard the plane.The plane crashed, killing all 157 passengers aboard.All aboard!(= the bus, boat, etc. is leaving soon)Welcome aboard!(= used to welcome passengers or a person joining a new organization, etc.)See related entries:Plane travel,Train and bus travel,Parts of boats and ships,Travelling by boat or shipWord Originlate Middle English: from a-‘to, towards’ (expressing motion) + board, reinforced by Old Frenchà bord.